Symbolic Simulation By Nodal Method Of Effective Branch Current Source

ome of the tasks that cannot be solved effectively by conventional simulation have become tractable by extending the simulation to operate a in symbolic domain. Symbolic simulation involves introducing an expanded set of signal values and redefining the basic simulation functions to operate over this expanded set. This enables the simulator evaluate a range of operating conditions in a single run. By linearizing the circuits with lumped parameters at particular operating points and attempting only frequency domain analysis, the program can represent signal values as rational functions in the s ( continuous time ) or z (discrete time) domain and are generated as sums of the products of symbols which specify the parameters of circuits elements [2 – 4]. Symbolic formulation grows exponentially with circuit size and it limits the maximum analyzable circuit size and also makes more difficult, formula interpretation and its use in design automation application [5 – 10]. This is usually improved by using semisymbolic formulation, which is symbolic formulation with numerical equivalent of symbolic coefficient. Other methods of simplification include simplification before generation (SBG), simplification during generation SDG, and simplification after generation (SAG) [11 – 17]. Symbolic response formulation of electrical circuit may be classified broadly as modified nodal analysis (MNA) [18], sparse tableau formulation and state variable formulation. The state variable method was developed before the modified nodal analysis, it involves intensive mathematical process and has major limitation in the formulation of circuit equations. Some of the limitations arise because the state variables are capacitor voltages and inductor currents [19]. The tableau formulation